<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            background-color: #ddd;
            /* line-height: 16px; */

            /* 如果没有加单位的时候，表示字体大小的倍数  16倍 */
            line-height: 16;
        }
    </style>
</head>

<body>

    <div>哈哈哈</div>

</body>

</html>